1. Technical Field
The present invention relates to a stamping device that stamps letters and the like on print media by pressing a stamp against the print media by means of a drive mechanism using a motor or other actuator. The invention also relates to a media processing device such as a check processing device having the stamping device.
2. Description of Related Art
A stamping device of this type is used in a check reader such as described in JP-A-2003-141367, for example. While conveying checks, promissory notes, and similar financial instruments (referred to as simply “checks” below) through a media transportation path, a check reader reads magnetic ink characters using a magnetic head disposed in the transportation path, images the check using a scanner, and then drives the stamping device to stamp the check with “PROCESSED,” for example, after scanning is completed.
If the drive mechanism of the stamping device fails to operate, such as when the drive mechanism stops because of a power failure during operation, the stamp may be left pressed against the paper or other print medium. If the stamp is left pressed against the print medium, ink will continue to be supplied from the transfer surface of the stamp to the print medium and the print medium may become soiled with ink. If the print medium is forcibly removed, the surface of the print medium becomes smeared with ink as the print medium is pulled over the surface of the stamp. After the print medium is removed, the stamp will also be left pressed directly against the guide surface that guides the print medium instead of against the print medium, and ink will soil the guide surface. If the guide surface becomes soiled with ink, the ink on the guide surface will then soil the back side of the next print medium when it passes over the guide surface for printing.
If the stamp, which is pushed by a drive mechanism using a motor or other actuator, of the stamping device is not pressed against the surface of the print medium with uniform pressure, ink transfer and stamp life, for example, will vary. In order to maintain uniform stamp pressure, the printing position where the stamp is pressed to the print medium must be managed with good precision. Variation in the printing position of the stamp necessarily occurs, however, as a result of dimensional variation in the parts in the stamp drive mechanism, differences in the assembly of the parts, and deviation in the detection precision of the detectors that detect stamp movement and position. It is therefore not possible to manage the stamping pressure of the stamp with good precision.